1. Field of the Invention
The present invention relates to a detector with a flexible cable for inputting/outputting signals to/from a circuit board, and a method of producing a detector.
2. Description of the Related Art
In the field of electronic equipment, various flexible cables are often used for inputting/outputting signals to/from circuit boards. Flexible cables are soft and thin, in addition to being inexpensive, and therefore it is possible not only to reduce the manufacturing costs, but also to realize a smaller size, in particular a reduced thickness, of the equipment. When a clamp-type connector is mounted on a circuit board of an electronic apparatus, the terminal part of the flexible cable is inserted into the clamp-type connector so that the metal terminal part of the clamp-type connector is pressed against the dielectric patterns of the terminal part of the flexible cable. Prior to the insertion, a reinforcement member having a high rigidity is often attached to the end part of the flexible cable which includes the terminal part, so as to ensure that the highly pliant flexible cable can be securely inserted into the clamp-type connector. Such a reinforcement member can also serve as a clamped part which is clamped together with the flexible cable by the clamp-type connector. In relation to this, JP-A-2006-228768 discloses a connection structure of an FFC and circuit board in which a reinforcement plate stuck to a back surface of the flexible flat cable (FFC) is inserted together with the FFC into an insertion slot of the circuit board. Furthermore, JP-A-2006-228768 proposes the art of using lock parts which are formed on the reinforcement plate of the FFC to protrude from both its side surfaces, so as to prevent the FFC from inadvertently being detached from the insertion slot.
FIG. 8 is a cross-sectional view which shows the structure of a conventional electronic apparatus, employing a reinforcement member which serves as a clamped part to be clamped by a clamp-type connector. The electronic device of FIG. 8 is an optical encoder comprising a slit disk 81 connected with a rotary member, a light emitting element 82 for emitting a light beam toward the slit disk 81, a light receiving element 83 for receiving a light pulse which passes through the slit disk 81, and a circuit board 84 on which the light receiving diode 83 is mounted. As shown in FIG. 8, a general, clamp-type connector 85 is also attached to the circuit board 84. A reinforcement member 87 stuck to the end part of the flexible cable 86 is inserted together with the flexible cable 86 into the clamp-type connector 85. Such an optical encoder is preferably small and thin, but to securely insert the flexible cable 86 and the reinforcement member 87 into the clamp-type connector 85, it is necessary that the reinforcement member 87 have a certain extent of height. However, if the reinforcement member 87 becomes larger in height, as shown in FIG. 8, the dimension of the detector ends up becoming larger in the height direction of the reinforcement member 87, and therefore the detector cannot achieve a smaller size, in particular a reduced thickness.
A detector which can realize smaller size, in particular, reduced thickness, even if a reinforcement member is attached to the flexible cable, is being sought.